PNNL

Abstract

Countries around the world are deploying radiation portal monitor (RPM) systems and other radiation detection instrumentation to interdict the illegal shipment of radioactive material crossing international borders. These efforts include deployments in the U.S. and in a number of other countries by governments and international organizations. Because of their high efficiency for gamma-ray detection, most deployed RPM systems are based on plastic scintillators. Such systems, however, are largely non-spectroscopic in capability. Fully capable spectroscopic portal monitor systems are undergoing engineering development for deployment in the future. The ability to identify the detected radionuclides may allow improved operational handling of radiation alarms, particularly those arising from the normal cargo stream of naturally occurring radioactive material, commercial radioactive sources, and individuals treated with medical radiopharmaceuticals. The goal for improved RPM systems is to increase the sensitivity to threats while reducing the impact that nuisance alarms have on operations. This paper considers the roles for spectroscopic and non-spectroscopic systems for safeguards and border security.